Analytic performance evaluation of opportunistic spectrum access with detection errors

This paper aims at giving some results on the performances of opportunistic spectrum access when taking into account sensing errors: non detection, which is the cause of collisions with a transmitting user, and false alarm, which is a cause of missed opportunity to access the channel. We give the probability An(i, j) of having i collisions and j successful access to the channel within n time slots when the primary users activity can be described by a two-state On/Off model. Our derivation allows us to take into account aggressive or conservative policy, that is to say the secondary user does not systematically obey the indication of the sensing stage, but with a given probability because the sensing is known to be prone to either false alarm or non detection with high probability.